CVE-2026-66274: Apache Qpid Proton-J: Unbounded type nesting can lead to pre-authentication stackoverflow

CVE-2026-66274 · Severity: high · CVSS 7.5 · Published 2026-08-05

A pre-authentication attacker could leverage type nesting to cause a StackOverflowError potentially leading to denial of service.

This issue affects Apache Qpid Proton-J: through 0.34.1.

Users are recommended to upgrade to version 0.35.0, which fixes the issue.

Technologies: org.apache.qpid:proton-j (Maven). Vendors: Maven.

Quick answers

Is CVE-2026-66274 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-66274 being exploited in the wild.
How severe is CVE-2026-66274?
High severity, with a CVSS score of 7.5, published 5 August 2026.
Which products and versions are affected?
org.apache.qpid:proton-j (Maven) < 0.35.0, ECOSYSTEM:introduced=0,fixed=0.35.0.
Is there a fix for CVE-2026-66274?
Yes. org.apache.qpid:proton-j (Maven): upgrade to 0.35.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-66274?
Check whether you run org.apache.qpid:proton-j (Maven) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • org.apache.qpid:proton-j (Maven): upgrade to 0.35.0 or later
    # set org.apache.qpid:proton-j to 0.35.0 in your pom.xml or build.gradle

Affected products

  • org.apache.qpid:proton-j (Maven) < 0.35.0, ECOSYSTEM:introduced=0,fixed=0.35.0

Identifiers

  • CVE-2026-66274
  • GHSA-p2gc-fm5w-94jj

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